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diff --git a/vendor/github.com/sirupsen/logrus/README.md b/vendor/github.com/sirupsen/logrus/README.md new file mode 100644 index 000000000..cbe8b6962 --- /dev/null +++ b/vendor/github.com/sirupsen/logrus/README.md @@ -0,0 +1,501 @@ +# Logrus <img src="http://i.imgur.com/hTeVwmJ.png" width="40" height="40" alt=":walrus:" class="emoji" title=":walrus:"/> [](https://travis-ci.org/sirupsen/logrus) [](https://godoc.org/github.com/sirupsen/logrus) + +Logrus is a structured logger for Go (golang), completely API compatible with +the standard library logger. [Godoc][godoc]. **Please note the Logrus API is not +yet stable (pre 1.0). Logrus itself is completely stable and has been used in +many large deployments. The core API is unlikely to change much but please +version control your Logrus to make sure you aren't fetching latest `master` on +every build.** + +**Seeing weird case-sensitive problems?** Unfortunately, the author failed to +realize the consequences of renaming to lower-case. Due to the Go package +environment, this caused issues. Regretfully, there's no turning back now. +Everything using `logrus` will need to use the lower-case: +`github.com/sirupsen/logrus`. Any package that isn't, should be changed. + +I am terribly sorry for this inconvenience. Logrus strives hard for backwards +compatibility, and the author failed to realize the cascading consequences of +such a name-change. To fix Glide, see [these +comments](https://github.com/sirupsen/logrus/issues/553#issuecomment-306591437). + +Nicely color-coded in development (when a TTY is attached, otherwise just +plain text): + + + +With `log.SetFormatter(&log.JSONFormatter{})`, for easy parsing by logstash +or Splunk: + +```json +{"animal":"walrus","level":"info","msg":"A group of walrus emerges from the +ocean","size":10,"time":"2014-03-10 19:57:38.562264131 -0400 EDT"} + +{"level":"warning","msg":"The group's number increased tremendously!", +"number":122,"omg":true,"time":"2014-03-10 19:57:38.562471297 -0400 EDT"} + +{"animal":"walrus","level":"info","msg":"A giant walrus appears!", +"size":10,"time":"2014-03-10 19:57:38.562500591 -0400 EDT"} + +{"animal":"walrus","level":"info","msg":"Tremendously sized cow enters the ocean.", +"size":9,"time":"2014-03-10 19:57:38.562527896 -0400 EDT"} + +{"level":"fatal","msg":"The ice breaks!","number":100,"omg":true, +"time":"2014-03-10 19:57:38.562543128 -0400 EDT"} +``` + +With the default `log.SetFormatter(&log.TextFormatter{})` when a TTY is not +attached, the output is compatible with the +[logfmt](http://godoc.org/github.com/kr/logfmt) format: + +```text +time="2015-03-26T01:27:38-04:00" level=debug msg="Started observing beach" animal=walrus number=8 +time="2015-03-26T01:27:38-04:00" level=info msg="A group of walrus emerges from the ocean" animal=walrus size=10 +time="2015-03-26T01:27:38-04:00" level=warning msg="The group's number increased tremendously!" number=122 omg=true +time="2015-03-26T01:27:38-04:00" level=debug msg="Temperature changes" temperature=-4 +time="2015-03-26T01:27:38-04:00" level=panic msg="It's over 9000!" animal=orca size=9009 +time="2015-03-26T01:27:38-04:00" level=fatal msg="The ice breaks!" err=&{0x2082280c0 map[animal:orca size:9009] 2015-03-26 01:27:38.441574009 -0400 EDT panic It's over 9000!} number=100 omg=true +exit status 1 +``` + +#### Case-sensitivity + +The organization's name was changed to lower-case--and this will not be changed +back. If you are getting import conflicts due to case sensitivity, please use +the lower-case import: `github.com/sirupsen/logrus`. + +#### Example + +The simplest way to use Logrus is simply the package-level exported logger: + +```go +package main + +import ( + log "github.com/sirupsen/logrus" +) + +func main() { + log.WithFields(log.Fields{ + "animal": "walrus", + }).Info("A walrus appears") +} +``` + +Note that it's completely api-compatible with the stdlib logger, so you can +replace your `log` imports everywhere with `log "github.com/sirupsen/logrus"` +and you'll now have the flexibility of Logrus. You can customize it all you +want: + +```go +package main + +import ( + "os" + log "github.com/sirupsen/logrus" +) + +func init() { + // Log as JSON instead of the default ASCII formatter. + log.SetFormatter(&log.JSONFormatter{}) + + // Output to stdout instead of the default stderr + // Can be any io.Writer, see below for File example + log.SetOutput(os.Stdout) + + // Only log the warning severity or above. + log.SetLevel(log.WarnLevel) +} + +func main() { + log.WithFields(log.Fields{ + "animal": "walrus", + "size": 10, + }).Info("A group of walrus emerges from the ocean") + + log.WithFields(log.Fields{ + "omg": true, + "number": 122, + }).Warn("The group's number increased tremendously!") + + log.WithFields(log.Fields{ + "omg": true, + "number": 100, + }).Fatal("The ice breaks!") + + // A common pattern is to re-use fields between logging statements by re-using + // the logrus.Entry returned from WithFields() + contextLogger := log.WithFields(log.Fields{ + "common": "this is a common field", + "other": "I also should be logged always", + }) + + contextLogger.Info("I'll be logged with common and other field") + contextLogger.Info("Me too") +} +``` + +For more advanced usage such as logging to multiple locations from the same +application, you can also create an instance of the `logrus` Logger: + +```go +package main + +import ( + "os" + "github.com/sirupsen/logrus" +) + +// Create a new instance of the logger. You can have any number of instances. +var log = logrus.New() + +func main() { + // The API for setting attributes is a little different than the package level + // exported logger. See Godoc. + log.Out = os.Stdout + + // You could set this to any `io.Writer` such as a file + // file, err := os.OpenFile("logrus.log", os.O_CREATE|os.O_WRONLY, 0666) + // if err == nil { + // log.Out = file + // } else { + // log.Info("Failed to log to file, using default stderr") + // } + + log.WithFields(logrus.Fields{ + "animal": "walrus", + "size": 10, + }).Info("A group of walrus emerges from the ocean") +} +``` + +#### Fields + +Logrus encourages careful, structured logging through logging fields instead of +long, unparseable error messages. For example, instead of: `log.Fatalf("Failed +to send event %s to topic %s with key %d")`, you should log the much more +discoverable: + +```go +log.WithFields(log.Fields{ + "event": event, + "topic": topic, + "key": key, +}).Fatal("Failed to send event") +``` + +We've found this API forces you to think about logging in a way that produces +much more useful logging messages. We've been in countless situations where just +a single added field to a log statement that was already there would've saved us +hours. The `WithFields` call is optional. + +In general, with Logrus using any of the `printf`-family functions should be +seen as a hint you should add a field, however, you can still use the +`printf`-family functions with Logrus. + +#### Default Fields + +Often it's helpful to have fields _always_ attached to log statements in an +application or parts of one. For example, you may want to always log the +`request_id` and `user_ip` in the context of a request. Instead of writing +`log.WithFields(log.Fields{"request_id": request_id, "user_ip": user_ip})` on +every line, you can create a `logrus.Entry` to pass around instead: + +```go +requestLogger := log.WithFields(log.Fields{"request_id": request_id, "user_ip": user_ip}) +requestLogger.Info("something happened on that request") # will log request_id and user_ip +requestLogger.Warn("something not great happened") +``` + +#### Hooks + +You can add hooks for logging levels. For example to send errors to an exception +tracking service on `Error`, `Fatal` and `Panic`, info to StatsD or log to +multiple places simultaneously, e.g. syslog. + +Logrus comes with [built-in hooks](hooks/). Add those, or your custom hook, in +`init`: + +```go +import ( + log "github.com/sirupsen/logrus" + "gopkg.in/gemnasium/logrus-airbrake-hook.v2" // the package is named "aibrake" + logrus_syslog "github.com/sirupsen/logrus/hooks/syslog" + "log/syslog" +) + +func init() { + + // Use the Airbrake hook to report errors that have Error severity or above to + // an exception tracker. You can create custom hooks, see the Hooks section. + log.AddHook(airbrake.NewHook(123, "xyz", "production")) + + hook, err := logrus_syslog.NewSyslogHook("udp", "localhost:514", syslog.LOG_INFO, "") + if err != nil { + log.Error("Unable to connect to local syslog daemon") + } else { + log.AddHook(hook) + } +} +``` +Note: Syslog hook also support connecting to local syslog (Ex. "/dev/log" or "/var/run/syslog" or "/var/run/log"). For the detail, please check the [syslog hook README](hooks/syslog/README.md). + +| Hook | Description | +| ----- | ----------- | +| [Airbrake "legacy"](https://github.com/gemnasium/logrus-airbrake-legacy-hook) | Send errors to an exception tracking service compatible with the Airbrake API V2. Uses [`airbrake-go`](https://github.com/tobi/airbrake-go) behind the scenes. | +| [Airbrake](https://github.com/gemnasium/logrus-airbrake-hook) | Send errors to the Airbrake API V3. Uses the official [`gobrake`](https://github.com/airbrake/gobrake) behind the scenes. | +| [Amazon Kinesis](https://github.com/evalphobia/logrus_kinesis) | Hook for logging to [Amazon Kinesis](https://aws.amazon.com/kinesis/) | +| [Amqp-Hook](https://github.com/vladoatanasov/logrus_amqp) | Hook for logging to Amqp broker (Like RabbitMQ) | +| [Bugsnag](https://github.com/Shopify/logrus-bugsnag/blob/master/bugsnag.go) | Send errors to the Bugsnag exception tracking service. | +| [DeferPanic](https://github.com/deferpanic/dp-logrus) | Hook for logging to DeferPanic | +| [Discordrus](https://github.com/kz/discordrus) | Hook for logging to [Discord](https://discordapp.com/) | +| [ElasticSearch](https://github.com/sohlich/elogrus) | Hook for logging to ElasticSearch| +| [Firehose](https://github.com/beaubrewer/logrus_firehose) | Hook for logging to [Amazon Firehose](https://aws.amazon.com/kinesis/firehose/) +| [Fluentd](https://github.com/evalphobia/logrus_fluent) | Hook for logging to fluentd | +| [Go-Slack](https://github.com/multiplay/go-slack) | Hook for logging to [Slack](https://slack.com) | +| [Graylog](https://github.com/gemnasium/logrus-graylog-hook) | Hook for logging to [Graylog](http://graylog2.org/) | +| [Hiprus](https://github.com/nubo/hiprus) | Send errors to a channel in hipchat. | +| [Honeybadger](https://github.com/agonzalezro/logrus_honeybadger) | Hook for sending exceptions to Honeybadger | +| [InfluxDB](https://github.com/Abramovic/logrus_influxdb) | Hook for logging to influxdb | +| [Influxus](http://github.com/vlad-doru/influxus) | Hook for concurrently logging to [InfluxDB](http://influxdata.com/) | +| [Journalhook](https://github.com/wercker/journalhook) | Hook for logging to `systemd-journald` | +| [KafkaLogrus](https://github.com/goibibo/KafkaLogrus) | Hook for logging to kafka | +| [LFShook](https://github.com/rifflock/lfshook) | Hook for logging to the local filesystem | +| [Logentries](https://github.com/jcftang/logentriesrus) | Hook for logging to [Logentries](https://logentries.com/) | +| [Logentrus](https://github.com/puddingfactory/logentrus) | Hook for logging to [Logentries](https://logentries.com/) | +| [Logmatic.io](https://github.com/logmatic/logmatic-go) | Hook for logging to [Logmatic.io](http://logmatic.io/) | +| [Logrusly](https://github.com/sebest/logrusly) | Send logs to [Loggly](https://www.loggly.com/) | +| [Logstash](https://github.com/bshuster-repo/logrus-logstash-hook) | Hook for logging to [Logstash](https://www.elastic.co/products/logstash) | +| [Mail](https://github.com/zbindenren/logrus_mail) | Hook for sending exceptions via mail | +| [Mongodb](https://github.com/weekface/mgorus) | Hook for logging to mongodb | +| [NATS-Hook](https://github.com/rybit/nats_logrus_hook) | Hook for logging to [NATS](https://nats.io) | +| [Octokit](https://github.com/dorajistyle/logrus-octokit-hook) | Hook for logging to github via octokit | +| [Papertrail](https://github.com/polds/logrus-papertrail-hook) | Send errors to the [Papertrail](https://papertrailapp.com) hosted logging service via UDP. | +| [PostgreSQL](https://github.com/gemnasium/logrus-postgresql-hook) | Send logs to [PostgreSQL](http://postgresql.org) | +| [Pushover](https://github.com/toorop/logrus_pushover) | Send error via [Pushover](https://pushover.net) | +| [Raygun](https://github.com/squirkle/logrus-raygun-hook) | Hook for logging to [Raygun.io](http://raygun.io/) | +| [Redis-Hook](https://github.com/rogierlommers/logrus-redis-hook) | Hook for logging to a ELK stack (through Redis) | +| [Rollrus](https://github.com/heroku/rollrus) | Hook for sending errors to rollbar | +| [Scribe](https://github.com/sagar8192/logrus-scribe-hook) | Hook for logging to [Scribe](https://github.com/facebookarchive/scribe)| +| [Sentry](https://github.com/evalphobia/logrus_sentry) | Send errors to the Sentry error logging and aggregation service. | +| [Slackrus](https://github.com/johntdyer/slackrus) | Hook for Slack chat. | +| [Stackdriver](https://github.com/knq/sdhook) | Hook for logging to [Google Stackdriver](https://cloud.google.com/logging/) | +| [Sumorus](https://github.com/doublefree/sumorus) | Hook for logging to [SumoLogic](https://www.sumologic.com/)| +| [Syslog](https://github.com/Sirupsen/logrus/blob/master/hooks/syslog/syslog.go) | Send errors to remote syslog server. Uses standard library `log/syslog` behind the scenes. | +| [Syslog TLS](https://github.com/shinji62/logrus-syslog-ng) | Send errors to remote syslog server with TLS support. | +| [TraceView](https://github.com/evalphobia/logrus_appneta) | Hook for logging to [AppNeta TraceView](https://www.appneta.com/products/traceview/) | +| [Typetalk](https://github.com/dragon3/logrus-typetalk-hook) | Hook for logging to [Typetalk](https://www.typetalk.in/) | +| [logz.io](https://github.com/ripcurld00d/logrus-logzio-hook) | Hook for logging to [logz.io](https://logz.io), a Log as a Service using Logstash | +| [SQS-Hook](https://github.com/tsarpaul/logrus_sqs) | Hook for logging to [Amazon Simple Queue Service (SQS)](https://aws.amazon.com/sqs/) | + +#### Level logging + +Logrus has six logging levels: Debug, Info, Warning, Error, Fatal and Panic. + +```go +log.Debug("Useful debugging information.") +log.Info("Something noteworthy happened!") +log.Warn("You should probably take a look at this.") +log.Error("Something failed but I'm not quitting.") +// Calls os.Exit(1) after logging +log.Fatal("Bye.") +// Calls panic() after logging +log.Panic("I'm bailing.") +``` + +You can set the logging level on a `Logger`, then it will only log entries with +that severity or anything above it: + +```go +// Will log anything that is info or above (warn, error, fatal, panic). Default. +log.SetLevel(log.InfoLevel) +``` + +It may be useful to set `log.Level = logrus.DebugLevel` in a debug or verbose +environment if your application has that. + +#### Entries + +Besides the fields added with `WithField` or `WithFields` some fields are +automatically added to all logging events: + +1. `time`. The timestamp when the entry was created. +2. `msg`. The logging message passed to `{Info,Warn,Error,Fatal,Panic}` after + the `AddFields` call. E.g. `Failed to send event.` +3. `level`. The logging level. E.g. `info`. + +#### Environments + +Logrus has no notion of environment. + +If you wish for hooks and formatters to only be used in specific environments, +you should handle that yourself. For example, if your application has a global +variable `Environment`, which is a string representation of the environment you +could do: + +```go +import ( + log "github.com/sirupsen/logrus" +) + +init() { + // do something here to set environment depending on an environment variable + // or command-line flag + if Environment == "production" { + log.SetFormatter(&log.JSONFormatter{}) + } else { + // The TextFormatter is default, you don't actually have to do this. + log.SetFormatter(&log.TextFormatter{}) + } +} +``` + +This configuration is how `logrus` was intended to be used, but JSON in +production is mostly only useful if you do log aggregation with tools like +Splunk or Logstash. + +#### Formatters + +The built-in logging formatters are: + +* `logrus.TextFormatter`. Logs the event in colors if stdout is a tty, otherwise + without colors. + * *Note:* to force colored output when there is no TTY, set the `ForceColors` + field to `true`. To force no colored output even if there is a TTY set the + `DisableColors` field to `true`. For Windows, see + [github.com/mattn/go-colorable](https://github.com/mattn/go-colorable). + * All options are listed in the [generated docs](https://godoc.org/github.com/sirupsen/logrus#TextFormatter). +* `logrus.JSONFormatter`. Logs fields as JSON. + * All options are listed in the [generated docs](https://godoc.org/github.com/sirupsen/logrus#JSONFormatter). + +Third party logging formatters: + +* [`logstash`](https://github.com/bshuster-repo/logrus-logstash-hook). Logs fields as [Logstash](http://logstash.net) Events. +* [`prefixed`](https://github.com/x-cray/logrus-prefixed-formatter). Displays log entry source along with alternative layout. +* [`zalgo`](https://github.com/aybabtme/logzalgo). Invoking the P͉̫o̳̼̊w̖͈̰͎e̬͔̭͂r͚̼̹̲ ̫͓͉̳͈ō̠͕͖̚f̝͍̠ ͕̲̞͖͑Z̖̫̤̫ͪa͉̬͈̗l͖͎g̳̥o̰̥̅!̣͔̲̻͊̄ ̙̘̦̹̦. + +You can define your formatter by implementing the `Formatter` interface, +requiring a `Format` method. `Format` takes an `*Entry`. `entry.Data` is a +`Fields` type (`map[string]interface{}`) with all your fields as well as the +default ones (see Entries section above): + +```go +type MyJSONFormatter struct { +} + +log.SetFormatter(new(MyJSONFormatter)) + +func (f *MyJSONFormatter) Format(entry *Entry) ([]byte, error) { + // Note this doesn't include Time, Level and Message which are available on + // the Entry. Consult `godoc` on information about those fields or read the + // source of the official loggers. + serialized, err := json.Marshal(entry.Data) + if err != nil { + return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err) + } + return append(serialized, '\n'), nil +} +``` + +#### Logger as an `io.Writer` + +Logrus can be transformed into an `io.Writer`. That writer is the end of an `io.Pipe` and it is your responsibility to close it. + +```go +w := logger.Writer() +defer w.Close() + +srv := http.Server{ + // create a stdlib log.Logger that writes to + // logrus.Logger. + ErrorLog: log.New(w, "", 0), +} +``` + +Each line written to that writer will be printed the usual way, using formatters +and hooks. The level for those entries is `info`. + +This means that we can override the standard library logger easily: + +```go +logger := logrus.New() +logger.Formatter = &logrus.JSONFormatter{} + +// Use logrus for standard log output +// Note that `log` here references stdlib's log +// Not logrus imported under the name `log`. +log.SetOutput(logger.Writer()) +``` + +#### Rotation + +Log rotation is not provided with Logrus. Log rotation should be done by an +external program (like `logrotate(8)`) that can compress and delete old log +entries. It should not be a feature of the application-level logger. + +#### Tools + +| Tool | Description | +| ---- | ----------- | +|[Logrus Mate](https://github.com/gogap/logrus_mate)|Logrus mate is a tool for Logrus to manage loggers, you can initial logger's level, hook and formatter by config file, the logger will generated with different config at different environment.| +|[Logrus Viper Helper](https://github.com/heirko/go-contrib/tree/master/logrusHelper)|An Helper around Logrus to wrap with spf13/Viper to load configuration with fangs! And to simplify Logrus configuration use some behavior of [Logrus Mate](https://github.com/gogap/logrus_mate). [sample](https://github.com/heirko/iris-contrib/blob/master/middleware/logrus-logger/example) | + +#### Testing + +Logrus has a built in facility for asserting the presence of log messages. This is implemented through the `test` hook and provides: + +* decorators for existing logger (`test.NewLocal` and `test.NewGlobal`) which basically just add the `test` hook +* a test logger (`test.NewNullLogger`) that just records log messages (and does not output any): + +```go +import( + "github.com/sirupsen/logrus" + "github.com/sirupsen/logrus/hooks/null" + "github.com/stretchr/testify/assert" + "testing" +) + +func TestSomething(t*testing.T){ + logger, hook := null.NewNullLogger() + logger.Error("Helloerror") + + assert.Equal(t, 1, len(hook.Entries)) + assert.Equal(t, logrus.ErrorLevel, hook.LastEntry().Level) + assert.Equal(t, "Helloerror", hook.LastEntry().Message) + + hook.Reset() + assert.Nil(t, hook.LastEntry()) +} +``` + +#### Fatal handlers + +Logrus can register one or more functions that will be called when any `fatal` +level message is logged. The registered handlers will be executed before +logrus performs a `os.Exit(1)`. This behavior may be helpful if callers need +to gracefully shutdown. Unlike a `panic("Something went wrong...")` call which can be intercepted with a deferred `recover` a call to `os.Exit(1)` can not be intercepted. + +``` +... +handler := func() { + // gracefully shutdown something... +} +logrus.RegisterExitHandler(handler) +... +``` + +#### Thread safety + +By default Logger is protected by mutex for concurrent writes, this mutex is invoked when calling hooks and writing logs. +If you are sure such locking is not needed, you can call logger.SetNoLock() to disable the locking. + +Situation when locking is not needed includes: + +* You have no hooks registered, or hooks calling is already thread-safe. + +* Writing to logger.Out is already thread-safe, for example: + + 1) logger.Out is protected by locks. + + 2) logger.Out is a os.File handler opened with `O_APPEND` flag, and every write is smaller than 4k. (This allow multi-thread/multi-process writing) + + (Refer to http://www.notthewizard.com/2014/06/17/are-files-appends-really-atomic/) |